from tkinter import *
from tkinter import filedialog
from PIL import Image, ImageTk, ImageDraw

IMAGE_SIZE = (350, 350)

photo = None


def upload():
    global photo
    path = filedialog.askopenfilename()
    if path:
        photo = Image.open(path)
        photo = photo.resize(IMAGE_SIZE)
        photo_tk = ImageTk.PhotoImage(photo)
        image_canvases[0].create_image(0, 0, image=photo_tk, anchor="nw")
        image_canvases[0].photo = photo_tk
        show_histogram(photo, original_image_histo)


def apply_filter(filter_name):
    global photo

    if filter_name == "Noir & Blanc":
        filtered_photo = photo.convert('L')
        canva = noir_blanc_canva
    elif filter_name == "Contour":
        filtered_photo = photo.convert("1")
        canva = contour_canva
    photo_tk = ImageTk.PhotoImage(filtered_photo)
    canva.create_image(0, 0, image=photo_tk, anchor="nw")
    canva.photo = photo_tk


def show_histogram(image, canva):
    # global histogram_photo
    histogram = image.histogram()

    histogram_image = Image.new("RGB", IMAGE_SIZE, "white")
    histogram_draw = ImageDraw.Draw(histogram_image)

    max_value = max(histogram)

    for i in range(256):
        bar_height = int(histogram[i] / max_value * IMAGE_SIZE[1])
        histogram_draw.line((i, IMAGE_SIZE[1], i, IMAGE_SIZE[0] - bar_height), fill=(i, i, i))

    histogram_photo = ImageTk.PhotoImage(histogram_image)
    canva.create_image(0, 0, image=histogram_photo, anchor="nw")
    canva.photo = histogram_photo

window = Tk()
window.geometry("850x750")
window.title("My interface")
window.config(bg="white")

buttons_frame = Frame(window, width=200, height=600, bg="white", pady=200)
buttons_frame.pack(side="left", fill='y')

load_button = Button(buttons_frame, text="Load image", command=upload, bg="light blue")
load_button.pack(side='top', pady=10)


nb_button = Button(buttons_frame, text="Convert N/B", command=lambda: apply_filter("Noir & Blanc"), bg="light blue")
nb_button.pack(side='top', pady=10)

contour_button = Button(buttons_frame, text="Contour", command=lambda: apply_filter("Contour"), bg="light blue")
contour_button.pack(side='top', pady=10)

images_frame = Frame(window, width=800, height=600, bg="white")
images_frame.pack(side='right', fill='both', expand=True)

image_canvases = []
for i in range(4):
    canvas = Canvas(images_frame, width=IMAGE_SIZE[0], height=IMAGE_SIZE[1], bg="white")
    canvas.grid(row=i//2, column=i%2)
    image_canvases.append(canvas)

original_image_canvas = image_canvases[0]
original_image_histo = image_canvases[1]
noir_blanc_canva = image_canvases[2]
contour_canva = image_canvases[3]
window.mainloop()